The present invention relates to a signal display element for the display of more than two informations for signal displays with electromagnetically excited tilting plates, having base plates, tilting plates supported in bearings and displaced axially in relation to each other, provided with at least one magnetic part and the magnetic axes of the magnetic parts are normal to the plane of the tilting plates, furtheron, bipolarly excitable electromagnets are contained which are well suitable for the control of the tilting plates; on the ends of the electromagnetic core facing the base plate guide plates parallel with the base plate are arranged.
As it is well known, signal display elements for the visual display of numbers, signals, symbols used to be applied such, as disclosed in Hungarian Patent HU-PS 157 250, which are provided with plates having magnetic parts and to be tilted by electromagnetic control and in such a manner that under the influence of the tilting motion one or the other face of the plates becomes visible, the plates can be tilted around a lateral edge or another edge being parallel with the lateral edge; the two surface of the tilting plates are carrying different informations, e.g. they are differently colored, while the part of the baseplate which became visible, carries an identical information this means, that it has the same color as the surface of tilting plate which became visible. The tilting plates are made--at least partly of a permanent magnetic material, and the magnetic axis thereof runs preferably perpendicular to the plane of the tilting plates. Accordingly, by the application of the signal display element two different informations can be displayed.
Furthermore, an element based on the principle of the previously described signal display is known, which is suitable for the display of more than two informations. This type of signal display element is specified in Hungarian Patent HU-PS 158 828. With this solution, in contrast to the earlier solution the axes of rotation of the signal display elements are not fixedly supported in bearings, but may move guided in the inside of U-shaped (hairpin) bearings, similarly, as books respectively covers provided with filler sheets. With this solution a plurality of tilting plates can be arranged in one tilting element and the number of displaying information is larger by one, than the number of the tilting plates (the same relates to the number of colors).
With both solutions the thickness of the single tilting plates is determined by required thickness (the required magnetic energy content) of the magnets with a magnetic axis being preferably normal to the plane of the tilting plates. The latter solution containing more tilting plates requires as many field coils, as the number of the tilting plates contained in the signal display element.
The invention is based on the recognition, with respect to a properly coded control of the field coils, and more particularly, if a plurality of tilting plates are applied in one signal display element, the number of the field coils can be considerably less, than the number of the tilting plates.
The essence of the invention lies in that the guide plates belonging to one signal display element are arranged with an axial displacement, while the number of the tilting plates is larger at least by one, than the number of the guide plates, however, it is less at least by one, than a power of two with an exponent corresponding to the number of the electromagnetic cores.